nfsd4: callback program number is per-session

The callback program is allowed to depend on the session which the
callback is going over.

No change in behavior yet, while we still only do callbacks over a
single session for the lifetime of the client.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4callback.c

@@ -498,6 +498,7 @@ int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
 		return -EINVAL;
 	if (conn->cb_minorversion) {
 		args.bc_xprt = conn->cb_xprt;
+		args.prognumber = clp->cl_cb_session->se_cb_prog;
 		args.protocol = XPRT_TRANSPORT_BC_TCP;
 	}
 	/* Create RPC client */

fs/nfsd/nfs4state.c

@@ -760,6 +760,7 @@ static struct nfsd4_session *alloc_init_session(struct svc_rqst *rqstp, struct n
 
 	new->se_cb_seq_nr = 1;
 	new->se_flags = cses->flags;
+	new->se_cb_prog = cses->callback_prog;
 	kref_init(&new->se_ref);
 	idx = hash_sessionid(&new->se_sessionid);
 	spin_lock(&client_lock);
@@ -782,7 +783,6 @@ static struct nfsd4_session *alloc_init_session(struct svc_rqst *rqstp, struct n
 		rpc_copy_addr((struct sockaddr *)&clp->cl_cb_conn.cb_addr, sa);
 		clp->cl_cb_conn.cb_addrlen = svc_addr_len(sa);
 		clp->cl_cb_conn.cb_minorversion = 1;
-		clp->cl_cb_conn.cb_prog = cses->callback_prog;
 		nfsd4_probe_callback(clp, &clp->cl_cb_conn);
 	}
 	return new;

fs/nfsd/state.h

@@ -96,7 +96,8 @@ struct nfs4_cb_conn {
 	/* SETCLIENTID info */
 	struct sockaddr_storage	cb_addr;
 	size_t			cb_addrlen;
-	u32                     cb_prog;
+	u32                     cb_prog; /* used only in 4.0 case;
+					    per-session otherwise */
 	u32			cb_minorversion;
 	u32                     cb_ident;	/* minorversion 0 only */
 	struct svc_xprt		*cb_xprt;	/* minorversion 1 only */
@@ -172,6 +173,7 @@ struct nfsd4_session {
 	struct nfsd4_channel_attrs se_fchannel;
 	struct nfsd4_channel_attrs se_bchannel;
 	struct list_head	se_conns;
+	u32			se_cb_prog;
 	u32			se_cb_seq_nr;
 	struct nfsd4_slot	*se_slots[];	/* forward channel slots */
 };